I hope you don't mind, but I just mirrored it on Github (https://github.com/seancron/kathack). You can use the following javascript to load it from the mirror.

    javascript:var i,s,ss=['https://github.com/seancron/kathack/raw/master/kh.js','http://ajax.googleapis.com/ajax/libs/jquery/1.5.1/jquery.min.js'];for(i=0;i!=ss.length;i++){s=document.createElement('script');s.src=ss[i];document.body.appendChild(s);}void(0);

P.S. If you do mind, just let me know and I'll take it down.